The HSP43216 Halfband Filter addresses a wide variety of applications by combining fS/4 (fS = sample frequency) quadrature up/down convert circuitry with a fixed coefficient halfband filter processor as shown in the block diagram. These elements may be configured to operate in one of the four following modes: decimate by 2 filtering of a real input signal; interpolate by 2 filtering of a real input signal; fS/4 quadrature down conversion of a real input signal followed by decimate-by-2 filtering to produce a complex analytic signal; interpolate-by-2 filtering of a complex analytic signal followed by fS/4 quadrature up conversion to produce a real valued output.

Features
• Sample Rates to 52MSPS
• Architected to Support Sample Rates to 104MSPS Using External Multiplexer
• Four Modes of Operation:
    - Interpolate by 2 Filtering
    - Decimate by 2 Filtering
    - Quadrature to Real Signal Conversion
    - fS/4 Quadrature Down Conversion Followed by Decimate by 2 Filtering
• 16-Bit Inputs and Outputs
• 67-Tap Halfband FIR Filter with 20-Bit Coefficients
• Two’s Complement or Offset Binary Outputs
• Programmable Rounding on Outputs
• 1.24:1 Filter Shape Factor
• >90dB Stopband Attenuation
• <0.0003dB Passband Ripple
• Saturation Logic on Output
• Pb-Free Available (RoHS Compliant)

Applications
• Digital Down Conversion
• D/A and A/D pre/post Filtering
• Tuning Bandwidth Expansion for HSP45116 and HSP45106